Styrene is classified as a possible human carcinogen by the EPA and by the International Agency for Research on Cancer (IARC). A voluntary compliance program has been adopted by industries using styrene.
Toxic chemicals leach out of these products into the food that they contain (especially when heated in a microwave). These chemicals threaten human health and reproductive systems.
These products are made with petroleum, a non-sustainable and heavily polluting resource. Polystyrene foam is often dumped into the environment as litter.